1. The Field of the Invention
The present invention relates to pumps for displacing fluid. More particularly, the present invention relates to mechanical pumps having a unitary construction for utilizing pumping force to displace a fluid.
2. The Relevant Technology
Mechanical pumps have been utilized for centuries to displace fluids. Modern mechanical pumps are utilized in manufacturing, residential applications, and in hydraulics. Modern pumps are often highly specialized for the application for which they are utilized. The components of the pumps are designed for optimal functionality and versatility.
Many components of mechanical pumps require seal elements to prevent leakage of the fluid being pumped while allowing movement of the movable elements. The use of seal elements increases the number of parts needed to manufacture the pump. Another drawback of seal elements is that they tend to deteriorate and fail more quickly than other pump components. This is due to the materials from which they are formed and the stresses to which they are subjected. Many pump manufacturers construct their pumps to allow replacement of the seal elements on a periodic basis. However, replacement of seal elements can be time consuming and expensive. This can be particularly true where servicing of the pump stops the manufacturing processes of a business. Additionally, the cost of replacement seal elements can be substantial.
Pumps utilized for some applications are subject to conditions and requirements that render the use of seal elements particularly problematic. For example, the use of seal elements can be problematic in pumps utilized in applications requiring ultra high purity of the fluid being pumped. The seal elements utilized in these pump are formed from rubbers, plastics, and/or other materials, which can be suitable for certain ultra high purity applications while being unsuitable for other ultra high purity applications. For example, a seal constructed of rubber can be suitable for the pumping of certain corrosive agents while being unsuitable for use in high temperature applications. In contrast, a plastic seal can be appropriate for high temperature settings but not for pumping certain corrosive agents. This requires that the pump be manufactured with seal elements tailored to the requirements of the fluid to be pumped and the operating conditions of the pump.
Another challenge presented by pumps utilized in ultra high purity applications is that some or all of the seal elements must be isolated from the fluid being pumped. However, failure of a seal or perforation of a diaphragm results in contact between the fluid and the seal elements. The materials used in manufacture of the seals can contaminate the fluid being pumped when contacted by the fluid. Because contamination of the fluid being pumped can result in millions of dollars of ruined product and/or machinery, the possibility of contamination due to perforation of the diaphragm or failure of a seal requires additional leak detection mechanisms for use with the pump.